Scintillators are widely used detectors for spectroscopy of energetic photons (e.g., X-rays and gamma-rays) as well as neutrons. These detectors are commonly used in nuclear and high energy physics research, medical imaging, diffraction, non-destructive testing, geological exploration, and other applications. Important properties for the scintillation crystals used in these applications include high light output, high gamma ray stopping efficiency (attenuation), fast response, low cost, good proportionality, minimal afterglow, and/or pulse shape discrimination. Thus, there is continued interest in the search for scintillator materials that have these properties.
At present, scintillation detectors based on commercially available organic liquids or plastics are often used for the detection of neutrons. These scintillators provide neutron detection via proton recoil due to their high hydrogen content. While these scintillators show fast response and are available in large sizes at relatively low cost, they have several performance limitations. Liquid scintillators provide neutron/gamma pulse shape discrimination (PSD), but they are based on organic compounds and have relatively low flash points (as low as 24° C., in some cases), and they can be relatively bulky and cumbersome to handle. The main limitation of current plastic scintillator materials for neutron detection is their inability to provide effective gamma-neutron discrimination on the basis of pulse shapes.